请教LTE 141标准中带内杂散测试的问题

wyqstrive

Df is the separation between the channel edge
frequency and the nominal -3dB point of the measuring filter closest to the carrier frequency.
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f_offset is the separation between the channel edge
frequency and the centre of the measuring filter.
-
f_offsetmax is the offset to the frequency 10 MHz outside the downlink operating band.
-
Dfmax is equal to f_offsetmax minus half of the bandwidth of the measuring filter.

原文中的measurement filter是指什么？有没有高人可以解释一哈子。